Typical self-service applications use formal categories to describe a domain in question. Examples of domains with known formal categories range from home furnishing to healthcare yet each domain is well described. Organizational adoption of these formal categories presume them to be well known to the consumers or patients therefore accordingly easily interpreted by the end users of the applications. Formal categories typically have category definitions strongly defined on underlying back-end systems. However, most users would rather explain associated real world needs or problems or healthcare concerns in respective terms, in free-form text, which may not align with the formal descriptions or categories provided.
Therefore, there are often attempts to map the real world needs and the formal categorization in order to bridge knowledge gap. For example within the field of information technology, operations including understanding and mapping techniques of a domain may be performed to ease the human computer interface. The validation process typically checks heuristics, to determine whether a system matches the real world. Even since, the validation check quite often fails when user interface terminology reflecting system-centric terms does not match the real world terminology and categorization of the users of the system.
There is nothing simple about operations including understanding queries or inputs of a user, responding with rich and appropriate computer generated responses, and then upon completion of a dialog, returning programmatically located valid knowledge or resources to the user in a response. User is not a term restricted to a human user but also can be another computing component including a software application or device.